Tanaka K, Aso B, Sugano M
J Nutr. 1984 Jan;114(1):26-32. doi: 10.1093/jn/114.1.26.
Male Wistar rats were fed 1% fat, cholesterol-free semipurified diets containing soybean protein isolate and casein or amino acid mixtures simulating these proteins for 28-30 days. The animals then underwent surgery for biliary diversion, and bile was collected for 2 hours. The rate of bile flow was not influenced by the type of dietary protein. The concentration and output of biliary cholesterol in rats fed soybean protein were significantly higher than in those fed casein, while biliary bile acid excretion was comparable. The group given the soy protein-type amino acid mixture also tended to excrete more biliary cholesterol relative to the casein-type amino acid mixture, although the difference was not significant, while biliary bile acid output was comparable. When 5% fat diets containing 0.5% cholesterol were given to rats, concentrations of both biliary cholesterol and bile acid were elevated significantly on a vegetable protein diet. In these experiments, there was a significant negative correlation between serum cholesterol and biliary cholesterol levels. Stimulation of the biliary excretion of cholesterol seems at least relevant to the cholesterol-lowering action of soybean protein.
将雄性Wistar大鼠喂食含1%脂肪、无胆固醇的半纯化日粮，日粮包含大豆分离蛋白和酪蛋白或模拟这些蛋白质的氨基酸混合物，持续28 - 30天。然后对动物进行胆管改道手术，并收集胆汁2小时。胆汁流速不受膳食蛋白质类型的影响。喂食大豆蛋白的大鼠胆汁中胆固醇的浓度和排出量显著高于喂食酪蛋白的大鼠，而胆汁酸排泄量相当。相对于酪蛋白型氨基酸混合物，给予大豆蛋白型氨基酸混合物的组也倾向于排泄更多的胆汁胆固醇，尽管差异不显著，而胆汁酸排出量相当。当给大鼠喂食含0.5%胆固醇的5%脂肪日粮时，植物蛋白日粮组的胆汁胆固醇和胆汁酸浓度均显著升高。在这些实验中，血清胆固醇和胆汁胆固醇水平之间存在显著的负相关。刺激胆汁胆固醇排泄似乎至少与大豆蛋白的降胆固醇作用有关。
